NASA reveals GROUNDBREAKING research on twin astronauts
Scott was on the ISS for a total of 340 consecutive days, during which he was monitored.
Supply vessels transported urine, blood and stool samples from Scott back to Earth.
Similar checks were carried out on Mark, who also used to be an astronaut.
Notably Scott experienced a noticeable thickening of his carotid artery, which Mark did not.
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